Hoses are common components of many forms of machinery, notably the automobile. Typically, they will form a conduit for liquid extending between sections of the machine that may be expected to have some small degree of relative motion with respect to each other. The ends of the hose are usually secured to tubular extensions by constricting clamps in which the constricting action is generated by either a mechanical arrangement, or by the resilience of the material of the clamp. This latter form of clamp has been developed to a point of admirable simplicity, and commonly consists of nothing more than a spiral turn of a rather heavy steel wire, the ends of which slightly overlap to produce the spiral rather than a purely circular configuration. The extreme ends of this piece of wire are bent into substantially radial extensions, which can be gripped by a pair of pliers and brought together to increase the diameter enclosed by the device. In this position, it may be slipped on or off the end of the tubing. On release of the radial ends, the resilience of the device constricts it about the hose, and holds it securely in position on the tubular extension with which it is associated.
Holding and manipulating these clamps with a pair of pliers requires a considerable skill, and it is obvious that the release of manual force from the pliers will produce a corresponding release of the clamp, unless the pliers are of the special form capable of maintaining its grip. Such pliers have a limit to the clamping travel of the jaws, which might not be adequate to loosen the hose clamp enough for an easy installation or removal.
Special tools have been devised that are capable of engaging the radial ends of this form of hose clamp, and bring them together to increase the effective diameter of the clamp through rotating the tool about an axis generally parallel to the radial end portions of the clamp. The rotation has the effect of applying a cam surface to at least one of the ends, and thus inducing the force necessary to overcome the spring resilience of the hardened steel wire. The tool configurations that have been developed to provide these cam surfaces have tended to be somewhat more complicated than now appears to be necessary. The present invention provides a low-cost simplification of this general type of tool.